| // Main page documentation for ANTLR3C runtime. Contains |
| // doxygen things only. |
| // |
| |
| /// \mainpage ANTLR3 C Runtime API and Usage Guide. |
| /// |
| /// \section version Version 3.3.1 |
| /// |
| /// This documentation is specifically for the C rutime version 3.1.x.x, which is |
| /// specifically for use with version 3.1.x.x of the ANTLR recognizer generation |
| /// tool. While some of the documentation may well apply to prior or future versions |
| /// you should consult the manuals for the correct version whenever possible. |
| /// |
| /// \section chchchchangeesss Changes from 3.2 to 3.3.1 |
| /// |
| /// Some changes in 3.3.1 may require small changes in your invoking programs or |
| /// in the grammar itself. Please read about them here before emailing the user group, |
| /// where you will be told to come and read about them here, unless they were missed |
| /// from this list. |
| /// |
| /// - \subpage changes331 Check here for API changes |
| /// |
| /// \section intro Introduction |
| /// |
| /// The ANTLR3 recognizer generation tool is written in Java, but allows the generation |
| /// of code targeted for a number of other languages. Each target language provides a code |
| /// generation template for the tool and a runtime library for use by generated recognizers. |
| /// The C runtime tracks the Java runtime releases and in general when a new version of the |
| /// tool is released, a new version of the C runtime will be released at the same time. |
| /// |
| /// The documentation here is in three parts: |
| /// |
| /// - \subpage build Building the runtime itself from source code; |
| /// - \subpage generate How to tell ANTLR to generate code for the C target; |
| /// - \subpage buildrec How to build the generated code |
| /// - \subpage using Using the runtime and the libraries and so on; |
| /// - \subpage runtime The documentation of the runtime code and functions; |
| /// |
| /// \section background Background Information |
| /// |
| /// The ANTLR 3 C runtime and code generation templates were written by <a href="http://www.linkedin.com/in/jimidle"> Jim Idle</a> |
| /// (jimi|at|temporal-wave|dott/com) of <a href="http://www.temporal-wave.com">Temporal Wave LLC</a>. |
| /// |
| /// The C runtime and therefore the code generated to utilize the runtime reflects the object model of the |
| /// Java version of the runtime as closely as a language without class structures and inheritance can. |
| /// Compromises have only been made where performance would be adversely affected such as minimizing the |
| /// number of pointer to pointer to pointer to function type structures that could ensue through trying to |
| /// model inheritance too exactly. Other differences include the use of token and string factories to minimize |
| /// the number of calls to system functions such as calloc().This model was adopted so that overriding any |
| /// default implementation of a function is relatively simple for the grammar programmer. |
| /// |
| /// The generated code is free threading (subject to the systems calls used on any particular platform |
| /// being likewise free threading.) |
| /// |
| /// \subsection model Runtime Model |
| /// |
| /// As there is no such thing as an object reference in C, the runtime defines a number of typedef structs that reflect |
| /// the calling interface chosen by Terence Parr for the Java version of the same. The initialization of a parser, |
| /// lexer, input stream or other internal structure therefore consists of allocating the memory required for |
| /// an instance of the typedef struct that represents the interface, initializing any counters, and buffers etc, |
| /// then populating a number of pointers to functions that implement the equivalent of the methods in the Java class. |
| /// |
| /// The use and initialization of the C versions of a parser is therefore similar to the examples given for Java, |
| /// but with a bent towards C of course. You may need to be aware of memory allocation and freeing operations |
| /// in certain environments such as Windows, where you cannot allocate memory in one DLL and free it in another. |
| /// |
| /// The runtime provides a number of structures and interfaces that the author has found useful when writing action and |
| /// processing code within java parsers, and furthermore were required by the C runtime code if it was not to |
| /// depart too far from the logical layout of the Java model. These include the C equivalents of String, List, |
| /// Hashtable, Vector and Trie, implemented by pointers to structures. These are freely available for your own programming needs. |
| /// |
| /// A goal of the generated code was to minimize the tracking, allocation and freeing of memory for reasons of both |
| /// performance and reliability. In essence any memory used by a lexer, parser or tree parser is automatically tracked and |
| /// freed when the instance of it is released. There are therefore factory functions for tokens and so on such that they |
| /// can be allocated in blocks and parceled out as they are required. They are all then freed in one go, minimizing the |
| /// risk of memory leaks and alloc/free thrashing. This has only one side effect, being that if you wish to preserve some structure generated by |
| /// the lexer, parser or tree parser, then you must make a copy of it before freeing those structures, and track it yourself |
| /// after that. In practice, it is easy enough just not to release the antlr generated components until you are |
| /// finished with their results. |
| /// |
| /// \section targets Target Platforms |
| /// |
| /// The C project is constructed such that it will compile on any reasonable ANSI C compiler in either 64 or 32 bit mode, |
| /// with all warnings turned on. This is true of both the runtime code and the generated code and has been summarily tested |
| /// with Visual Studio .Net (2003, 2005 and 2008) and later versions of gcc on Redhat Linux, as well as on AIX 5.2/5.3, Solaris 9/10, |
| /// HPUX 11.xx, OSX (PowerPC and Intel) and Cygwin. |
| /// |
| /// \b Notes |
| /// - The C runtime is constructed such that the library can be integrated as an archive library, or a shared library/DLL. |
| /// - The C language target code generation templates are distributed with the source code for the ANTLR tool itself. |
| /// |
| /// \section performance Performance |
| /// |
| /// It is C :-). Basic testing of performance against the Java runtime, |
| /// using the JDK1.6 java source code, and the Java parser provided in the examples (which is a tough test as it includes |
| /// backtracking and memoization) show that the C runtime uses about half the memory and is between 2 and 3 times the speed. |
| /// Tests of non-backtracking, non-memoizing parsers, indicate results significantly better than this. |
| /// |
| /// \section examples Downloading Examples |
| /// |
| /// The <a href="http://www.antlr.org/download.html">downloads page</a> of the ANTLR web site contains a downloadable |
| /// zip/tar of examples projects for use with the C runtime model. It contains .sln files and source code for a |
| /// number of example grammars and helps to see how to invoke and call the generated recognizers. |
| /// |